THE CELL Structures and Functions

The Cell Outside of cells is extracellular fluid.Outside of cells is extracellular fluid. Inside the cell is an aqueous solution called cytosol in which many organelles are suspended.Inside the cell is an aqueous solution called cytosol in which many organelles are suspended. The cell membrane separates the cytosol from the extracellular fluid.The cell membrane separates the cytosol from the extracellular fluid.

Cell Membrane Controls what enters and exits the cellControls what enters and exits the cell Gives the cell shape and supportGives the cell shape and support Composed of a bilayer (double layer) of lipid (fat) molecules. These molecules are called phospholipids.Composed of a bilayer (double layer) of lipid (fat) molecules. These molecules are called phospholipids. Proteins and carbohydrates are embedded in the phospholipid bilayer.Proteins and carbohydrates are embedded in the phospholipid bilayer. Found in both plant and animal cells.Found in both plant and animal cells.

Cell Membrane Each phospholipid consists of a head that is hydrophilic and two tails that are hydrophobic.Each phospholipid consists of a head that is hydrophilic and two tails that are hydrophobic. Hydrophilic = water lovingHydrophilic = water loving Hydrophobic = water fearingHydrophobic = water fearing

Cell Wall Gives the cell structure and shape.Gives the cell structure and shape. Lining surrounding the cell membrane.Lining surrounding the cell membrane. Found only in plant cells.Found only in plant cells.

Cytoplasm Jelly-like substance located between the nucleus and cell membrane.Jelly-like substance located between the nucleus and cell membrane. Nutrients are absorbed, transported, and processed.Nutrients are absorbed, transported, and processed. All organelles are suspended by this fluid called cytoplasm.All organelles are suspended by this fluid called cytoplasm.

Nucleus The control centre of the cell; directs all of the cell’s activitiesThe control centre of the cell; directs all of the cell’s activities The nucleus is separated from the cytoplasm by the nuclear envelope. The envelope is filled with nucleic acids, such as DNA and RNA.The nucleus is separated from the cytoplasm by the nuclear envelope. The envelope is filled with nucleic acids, such as DNA and RNA. Found in both plant and animal cells.Found in both plant and animal cells.

Ribosomes Produce proteinsProduce proteins Can be free-floating or attached to membranes.Can be free-floating or attached to membranes. Found in both plant and animal cells.Found in both plant and animal cells.

Endoplasmic Reticulum (ER) Membranous tubes and canals that connect with the nuclear envelope.Membranous tubes and canals that connect with the nuclear envelope. There are two types of ER:There are two types of ER: –Rough ER: containing attached ribosomes and thus manufacture proteins. –Smooth ER: manufacture fat molecules The products of the ER pinch off as vesicles and travel to the golgi apparatus.The products of the ER pinch off as vesicles and travel to the golgi apparatus. Found in both plant and animal cells.Found in both plant and animal cells.

Golgi Apparatus Membranous tubes that are stacked. Chemically change the protein and fat produced in the ER and are packaged into vesicles. These vesicles then travel through the cytoplasm and release the contents in the extracellular fluid to be used by cells. Found in both plant and animal cells.

Lysosomes Some vesicles produced by the golgi apparatus are lysosomes.Some vesicles produced by the golgi apparatus are lysosomes. Contain proteins and can digest particles as well as potentially dangerous microorganisms (bacteria or viruses) that could harm the cell.Contain proteins and can digest particles as well as potentially dangerous microorganisms (bacteria or viruses) that could harm the cell. Called “suicide sacs” because they can decompose an entire cell if it is old or damaged.Called “suicide sacs” because they can decompose an entire cell if it is old or damaged. Found only in animal cells.Found only in animal cells.

Mitochondria The powerhouse of the cell. Carries out cellular respiration. Cells which require large amounts of energy, such as muscle cells, will contain large numbers of mitochondria. Found in both plant and animal cells.

Vacuoles Membrane-bound sacs filled with a watery solution containing sugars, minerals, and proteins.Membrane-bound sacs filled with a watery solution containing sugars, minerals, and proteins. The water creates a pressure which helps keep the cell membrane pressed firmly against the cell.The water creates a pressure which helps keep the cell membrane pressed firmly against the cell. Plant cells have large vacuoles which results in the firm texture of vegetables such as celery.Plant cells have large vacuoles which results in the firm texture of vegetables such as celery. Found in both plant and animal cells.Found in both plant and animal cells.

Chloroplasts Carry out photosynthesis. Contains the green pigment chlorophyll which helps begin the process of photosynthesis and gives plants their green colour. Found only in plant cells and algae.

Cell Structure vs. City Structure Cell Structure City Structure Function Nucleus King’s Castle Control for all activities DNAKing/Queen Controlling body RibosomesMerchants Production of products ER Secret Passages Transport of important materials Golgi Apparatus Sewage system Packaging and Secretion LysosomesGuards Fights off intruders Cytoplasm Infrastructure & logistics Movement Mitochondria Power Supply Provides energy for all activities Cell membrane City wall Protection, limits VacoulesRooms Storage for materials